Dirt

I was reading the owners manual and the section on gasoline
says that while 91 octane gasoline is recommended, the car
will run on 87 octane gasoline. Knowing, of course, that
everyone is going to tell me,

"For the love of God, man, DON'T DO IT!"

does anyone have any experience running 87 octane gas
in a 1.8T engine? I would expect the associated reduction in
engine performance because, presumably, the engine computer
will retard the ignition timing to suite.

pmmccoy

I hate to sound like a cheap SOB but I've run my '98 2.8Q on 87 since day 1. I have 134k and have never had a problem. I tried a few consecutive tanks with premium but didn't notice a significant difference.

Mpls

Havn't noticed anything until recently on the forum where people say not to do it....IF you have a turbo engine (I have the 03' 1.8T, used to have 96 2.8 with 96,000 on it and got used to 87 octane).

Starting tonight...my gas light is on now...I am going to begin using <91 octane.
I will let you know if there is a difference, which I am hoping for because my 96' 2.8 could kill my 03 1.8T, but when I bought people said there is a break in period for new engines, but its still not as fast as I had hoped for after 4500 mi.
I still love the new car. Despite brake squealing and my shift **** coming off today, and is all loose.

Ler

I've alternated between 87, 89, and 91 and for day to day driving, it's hard to tell the difference. In terms of efficiency, they're more or less within 1 mpg of each other. That makes it kinda hard to rule out driving habits.
It does seem like (subjectively) the engine is revving higher with 87 whenever I move from a stop or merge on the freeway. At WOT, it feels less powerful, but not strikingly enough for me to attribute it solely to the fuel. My feeling is that 87 should be fine for normal driving and commuting. If you're a leadfoot, 91 or higher might be the better answer.

Avant XP

I imagine you're cheating yourself out of 5-10% of power. How much did u pay for the A4 again?

Audi Junkie

big difference, dude. If you have ever been to a track, they have the 100 and 110 pumps right there.